It has been documented that NGF and other neurotrophins (BDNF, NT-3 and NT-4/5) play a significant role in pathology for example pain due to osteoarthritis, pancreatitis, rheumatoid arthritis, psoriasis, pruritis and multiple sclerosis (Watanabe et al., 2008 J Neurosci Res. 86(16):3566-74; Raychaudhuri et al., 2011 Arthritis Rheum. 63(11):3243-52; Barthel et al., 2009 Arthritis Res Ther. 11(3):R82; Truzzi et al., 2011 Cell Death Differ. 18:948-58; McDonald et al., 2011 Curr Med Chem. 18:234-44; Yamaoka et al., 2007 J Dermatol Sci. 46(1):41-51). It has been demonstrated that selective antibodies to any of the neutrophins; either NGF or BDNF, NT-3 and NT-4/5 significantly reduce pain. Furthermore, antibodies directed to the neurotrophin receptors p75NTR Trk A, Trk B or Trk C have also been demonstrated to be efficacious in models of pain (Orita S et al., 2010 J Orthop Res. 28:1614-20; Svensson P et al., 2010 Pain. 148:473-80; Iwakura et al., 2010 J Hand Surg Am. 35:267-73; Cirilio et al., 2010 Cell Mol Neurobiol. 30:51-62; Pezet et al., 2010 Pain. 90:113-25; Hayashi et al., 2011 J Pain. 12:1059-68; Chu et al., 2011 Pain. 152:1832-7; Ueda et al., 2010 J Pharmacol Sci.; 112:438-43; Ghilardi et al., 2010 Bone. 48:389-98; Fukui et al., 2010 J Orthop Res. 2010; 28:279-83). Fukui et al., (2010) in a model of pain (mechanical allodynia following sciatic nerve crush) demonstrated significant efficacy on pain related endpoints following treatment with an anti-p75NTR antibody. It was concluded from this study that the treatment with a p75NTR inhibitory antibody reduced CGRP and p75NTR expression resulting in a significant reduction in pain.
The p75 neutrophic receptor (p75NTR) is a member of the tumor necrosis factor receptor superfamily (TNFR-SF) known to bind to neurotrophic growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and neurotrophin 4/5 (NT-4/5). p75NTR undergoes sequential proteolytic cleavage by α-secretase and γ-secretase activities and matrix metalloproteinases (MMPs), releasing its intracellular domain (ICD) into the cytoplasm, in a manner analogous to the cleavage-dependent signaling pathway of Notch and β-amyloid precursor protein (Jung et al., 2003 J Biol Chem 278:42161-42169; Kanning et al., 2003 J Neuro-sci 23:5425-5436). Cytoplasmic release of the p75NTR ICD by this pathway promotes signaling by associated NRIF (Kenchappa et al., 2006 Neuron 50:219-232).
The role of the extracellular domain of p75NTR, following the proteolytic cleavage by α-secretase and γ-secretase activities and MMPs is not fully understood. However this molecule has been shown by the present applicants to be useful in the treatment of pain (WO2013/136078). The protein has also been advantageously coupled to Fc antibody fragments in the form of a fusion protein by the present applicants (PCT/GB2014/052833).
The present application relates to an improved p75NTR-Fc fusion protein.